Three coastal California communities recently filed lawsuits against some of the biggest fossil fuel companies in the world. The communities say those companies should pay for the damage caused by rising seas because they knew about climate change and still contributed to it. NPR's Nathan Rott has more.

NATHAN ROTT, BYLINE: Imperial Beach, Calif., is surrounded by water on three sides.

SERGE DEDINA: We're on spit, basically, kind of a peninsula here.

ROTT: The town's mayor, Serge Dedina, is driving us through a residential area towards a public beach...

DEDINA: We're just north of the Mexican border, so you can see Mexico down there.

ROTT: ...To show some of the problems that come with being surrounded by so much water.

DEDINA: Basically, what's been happening is water starts bubbling up under the houses now. It's coming up under the street. So in the winter, this essentially is full-time always flooded now. And it just started happening the last few years.

ROTT: Last winter, he says, during a storm, seawater was pouring over the streets.

DEDINA: That's - it was actually really scary to see that. Like, it's, oh, this is what's coming at us. It's not something that we have to imagine. It's something that's happening right now.

ROTT: That something is sea-level rise. As temperatures increase and the polar ice sheets melt, scientists say that ocean levels will rise here and along the Pacific coast. The predictions vary, but a recent report says that a foot of sea level rise in this part of Southern California is virtually unavoidable by the end of the century. And it's likely to happen far sooner. On the beach next to a row of homes, Dedina says that presents low-lying Imperial Beach with a really tough question.

DEDINA: How do you pay for the street that we're going to lose and the public access, right? So you're losing access to a resource. And number two, ultimately, the loss of revenue from the fact that at some point these houses might not be here.

ROTT: The cost along Imperial Beach's coastline alone, Dedina says, are expected to exceed a hundred million dollars - way more than the city can afford. This is the poorest city in San Diego County. So he and two other California counties that are facing the same sort of problems decided to look for help footing the bill by suing 37 of the biggest oil, gas and coal companies in the world.

The thrust of their lawsuit - that those companies knew about climate change. They planned for it themselves. But they concealed the dangers and, quote, "engaged in massive campaigns," unquote, to undermine efforts to regulate their products. It's similar to how health advocates targeted tobacco companies in the '80s.

ANN CARLSON: I think it's an incredibly smart and well-crafted approach to using litigation to really try to address some of the challenges of climate change.

ROTT: Ann Carlson is the co-director of the Emmett Institute on Climate Change and The Environment at UCLA. She's also - full disclosure - advising the lawyers that brought this case, not for financial reasons - she says she's not being paid - but because she says she feels like climate change needs to be addressed.

CARLSON: And frankly, at a time when the United States is abdicating its leadership responsibilities, I think we need to press again on all fronts.

ROTT: Now, these aren't the first lawsuits of this nature that have been filed against big polluters. Similar efforts have failed. But Carlson thinks that these have a better chance for a couple of reasons. First, the science around climate change and the damages it can cause has only gotten stronger with time. Secondly, there's more evidence now - reporting and documents - showing that some of these companies did in fact know about the dangers of climate change.

CARLSON: And yet, engaged in a concerted campaign to try to cover up what was going on.

ROTT: Those make it easier to show a direct line between how the actions of the defendants caused the damages to the plaintiffs. But that doesn't mean it's cut and dry. Michael Burger is the executive director of the Sabin Center for Climate Change Law, and he says the toughest question these lawyers have to answer...

MICHAEL BURGER: Is why these particular actors should be held responsible for a global pollution problem that involves pretty much every human being on the face of the planet.

ROTT: NPR reached out to four of the largest companies in the lawsuit, and none responded. But the American Petroleum Institute, without directly addressing the litigation, said, quote, "the natural gas and oil industry is committed to addressing the challenge of global climate change."

ROTT: Back in Imperial Beach, Serge Dedina says he knows the lawsuit might seem like a long shot, but he says...

DEDINA: We'll take our chances any day in court over the reality of the floodwaters and waves that are coming at us.